/Engine/Plugins/Enterprise/DatasmithImporter/Source/ExternalSource/Public/ExternalSource.h
typedef [TOptional](API\Runtime\Core\IO\TOptional)< [TPromise](API\Runtime\Core\Async\TPromise)< [TSharedPtr](API\Runtime\Core\Templates\TSharedPtr)< [IDatasmithScene](API\Runtime\DatasmithCore\IDatasmithScene) > > > FOptionalScenePromise